Spectrally sensitized silver halide photographic emulsions

ABSTRACT

an internal latent image type silver halide photographic emulsion which provides a direct positive image by surface development in the presence of a fogging agent and which is useful in a light-sensitive material for the diffusion transfer process, which emulsion is spectrally sensitized with a supersensitizing combination of at least one sensitizing dye represented by the following general formula (I) or (II) ##STR1## wherein Z 1  represents a non-metallic atomic group necessary to complete a 5- or 6-membered heterocyclic ring; and R 1  and R 2 , which may be the same or different, each represents an alkyl group; ##STR2## wherein Z 2  represents a non-metallic atomic group necessary to complete a 5- or 6-membered heterocyclic ring; R 3  represents an alkyl group or an aryl group; R 4  represents an alkyl group or a substituted alkyl group; R 18  represents a hydrogen atom or an alkylene group necessary to complete a ring when R 4  and R 18  combine to form a ring; and Y represents an oxygen atom or ═N--R 19  wherein R 19  represents a hydrogen atom, an alkyl group or an aryl group; and at least one sensitizing dye represented by the following general formula (III), (IV), (V), (VI) or (VII) ##STR3## WHEREIN V 1 , V 2 , W 1  and W 2 , which may be the same or different, each represents a hydrogen atom, a halogen atom, a trifluoromethyl group, a cyano group, a carboxy group, an alkoxycarbonyl group, an aminosulfonyl group or an alkylsulfonyl group; R 5 , R 6 , R 7  and R 8 , which may be the same or different, each represents an alkyl group or a substituted alkyl group; X 1  represents an acid anion; and n 1  represents 0 or 1; ##STR4## WHEREIN V 1 , V 2 , R 5  and R 6 , which may be the same or different, each has the same meaning as defined in general formula (III); R 9 , R 10  and R 11 , which may be the same or different, each represents an alkyl group or a substituted alkyl group; X 2  represents an acid anion; n 2  represents 0 or 1; and W 3  and W 4 , which may be the same or different, each represents a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, a hydroxy group, an acyloxy group or a phenyl group; ##STR5## wherein V 1 , V 2 , R 5  and R 6 , which may be the same or different, each has the same meaning as defined in general formula (III); W 5  and W 6 , which may be the same or different, each represents a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, a hydroxy group, an acyloxy group or a phenyl group; R 12  represents an alkyl group or a substituted alkyl group; X 3  represents an acid anion; and n 3  represents 0 or 1; ##STR6## wherein V 3  and W 7 , which may be the same or different, each represents a hydrogen atom, an alkyl group, an alkoxy group, a hydroxy group, an acyloxy group or a phenyl group; R 13  represents an alkyl group; R 14  and R 15 , which may be the same or different, each represents an alkyl group or a substituted alkyl group; X 4  represents an acid anion; and n 4  represents 0 or 1; ##STR7## wherein V 4  represents a hydrogen atom, a halogen atom, an alkyl group, a hydroxy group, an acyloxy group or a phenyl group; Z 3  represents an oxygen atom, a sulfur atom, a selenium atom or --CH═CH--; W 8  and W 9 , which may be the same or different, each represents a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, a hydroxy group or a phenyl group; R 16  and R 17 , which may be the same or different, each represents an alkyl group or a substituted alkyl group; X 5  represents an acid anion; and n 5  represents 0 or 1.



